HW6
		Due Thursday, April 9

NOTE:  Although we informally talk about BDDs below, we always mean
        ROBDD (Reduced Ordered BDD).

1.  Given the logic formula,
  F1:  (p1 or p2) implies (p1 and p2)
  Draw a BDD for F1 with Boolean variable p1 first, then p2.
  Also state how many different combinations of values for (p1,p2)
	will satisfy F1.

2.  Given the logic formula,
  F2:  not(p1 and p2) implies (p1 or p3)
  Draw a BDD for F2 with Boolean variable p1 first, then p2, then p3.
  Also state how many different combinations of values for (p1,p2)
	will satisfy F2.

3.  Draw the BDD for (F1 and F2).
  Also state how many different combinations of values for (p1,p2,p3)
	will satisfy (F1 and F2).

4.  Look at the BDD that you produced in problem 3, and find a compact
      logical expression in terms of p1, p2, and p3 that describes (F1 and F2).

5.  Given Boolean variables p1, p2 and p3, a parity check formula
      F(p1, p2, p3) is a formula that produces 1 (true) if exactly an even
      number of the variables (zero or two variables in this case)
      have the value 1 (true).	Otherwise, it produces 0 (false).
    In logic, we could express this as:
      (p1 and p2 and not p3) or (p1 and p3 and not p2)
	 or (p2 and p3 and not p1) or (not p1 and not p2 and not p3)
    Draw the BDD for F(p1, p2, p3).

6.a.  If a BDD has 7 nodes, then what is the maximum number of entries
	in the unique table of the BDD?  (Assume a single BDD for the
	entire BDD.  Note that unique tables are described in the
	course web page on BDDs.)
6.a.  If one BDD has 7 nodes, and another BDD has 8 nodes, then what is the
	maximum number of entries in the unique table for the new BDD
	given as the logical and of the two previous BDDs?